In examinations one of the first questions will probably
for you to work out the 'gear ratio'
(sometimes called velocity ratio). As a
guide - always assume that the larger gear revolves one revolution. The
number of rotations of the second gear has then to be worked out.

In the example below, the DRIVER
has 60 teeth and because it is the largest we say that it revolves once. The
DRIVEN gear has 30 teeth. Simply divide 60 teeth by 30 teeth to work out the
number of revolutions of the driven gear.